[presubmit] Enable readability/namespace linter checking.

src/libplatform/task-queue.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/libplatform/task-queue.h"
 
 #include "src/base/logging.h"
 
 namespace v8 {
 namespace platform {
@@ skipping 35 matching lines @@
 }
 
 
 void TaskQueue::Terminate() {
   base::LockGuard<base::Mutex> guard(&lock_);
   DCHECK(!terminated_);
   terminated_ = true;
   process_queue_semaphore_.Signal();
 }
 
-} }  // namespace v8::platform
+}  // namespace platform
+}  // namespace v8